b)This paper is dedicated to the memory of Professor David J. H. Cockayne FRS, 1942–2010. He will be well remembered for his very significant contributions to science, as well as his warm and engaging manner.

Abstract

Low optical and mechanical loss amorphous coatings have a growing number of applications in precision optical measurements systems. Transmission electron microscopy is a promising way to probe the atomic structure of these coatings in an effort to better understand the causes of the observed mechanical and optical losses. Analysis of the experimental reduced density functions using a combination of reverse Monte Carlo refinements and density functional theorymolecular dynamics simulations reveals that the structure of amorphous consists of clusters with increased contribution from a ring fragment.

Received 16 August 2010Accepted 16 December 2010Published online 19 January 2011

Acknowledgments:

We would like to thank our colleagues at the IGR, GEO, and LIGO Scientific collaborations for useful discussions, especially Professor M. M. Fejer. We wish to acknowledge the use of the Chemical Database Service at Daresbury. We would also like to thank STFC (Grant No. PP/F00110X/1), SFC, and the University of Glasgow in the U. K. and the NSF (Grant No. PHY-0757058) in the USA for financial support. RB is grateful to the EPSRC for the provision of a DTA studentship.